shreeve



Dec. 27, 1927..

. Re, 16,835 H. E. SHREEVE v SIGNALING SYSTEM Orizinal Filed Sept. 17, 1913 2 Sheets-Sheet l F I hue/7hr.-

' fierberffiS/veeve H. E. SHREEVE SIGNAL'LNC:

SYSTEM e.. 7 n@ M mm W5. m m 2 33% Original Filed Sept. 17, 1918 Reiuued Dec. 27, 1921;

STAT

' ,iiiivelition relates to signaling 'sysems, and rtiore particularly to combined nd radio si nalingsystems. Aii'objectfof the invention is to provide i alingi systen'i for connecting two sepa- 12% statidns by asymmetric channels. Another object of the invention is to .provide atelephone system for'connecting two ,si ubscrib'ers stations by combined wire and radio. links. further object of the invention is to provide-a central station with means for censiiegiting an incoming signaling line to idi'fio' ttaiisifiitting and receiving stations.

still fut'ther object of the invention is to provide meansat a central station wherea two-wire telephone circuit maybe simultaneously connected to one two-Wire transmitting circuit leading to a radio 9 transmitting station, and another two-wire "Jreceiying circuit leading from a radio Ireiweivjnr station. An additional object of the invention is i to proyide at a "central station connecting a telephbnsubscribers station to radio transflitting and receiving stations,meuns for keeping the electrical characteristics of the i central station and its associated apparatus balanced with respectto the connections to theradio stations. In the drawing, Figure 1 illustrates dia- I granfitnaticallythe general scheme of signa'ling'circuits between a telephonesubscribers Qiit aild a radio transmitting station and E radiofreceivin station; Fig. 2 illustrates a scheme of cor circuits at the central stationl" ,1 y t Referring to Fig. 1 of the drawing, the

si aling station is connected by a twowiretwo way transmission circuit 1 to a ceiitral station B at which the two-way tifanhinission circuit is connected to two two- "Wire oneway transmission circuit-s, the incoining or listening circuit leading from a radioureceiving station C and an outgoing oi talking circuit leading to a radio transmission station Station A is represented dilt'gtfamniatically in the drawino as a telesubscribers station, but dbviously it ma H be an ordinary manual or printing tclc I h station or in fact, any other form of turbine si naling device or selecting apparatus." Stallion A is one ofa number of simi: lai stiitioiig' each of which is connected by v 1 Ramses PATENT OFFICE.

mmm'r n. spasms, of WYOMING, nnw mnsniri sssmaomo A'iuniican ms. moan AND TELEGRAPH 00:1 am: A conromrrion on NEW YORK.

smnamne SYSTEM.

.on iflair'o. naraaaz, dated May 24, 1921; Serial nmfas iatoaniea September 17; 1918; Application fo mama filed May 21, 1923. Serial no. 840,598." v l two-Way transmission circuits '1, 2, 3, re-

sectively, to jacks J J J 3 at the central s ation. The cord circuit included at the central station terminates in a plug whichf serves to connect the subscriber to the operators circuit having a series winding ito which the incoming one-way transmission line 5 is inductively connected, and

a shunt winding conjugately related to the series winding and across which the outgoing one'way transmission line 8 is connected. balancing network at the central station tosimulate the impedance'of lines 1, 2,3 and their connected apparatus is indicated generally by element 7 P P P Land P P J areconventional plug and jack arrangements for connecting the incoming lines!) and the outgoing lines 8 to the central station circuit.

Radio receiving station C comprisesan antenna 9, a. detector 10, preferably of the vacuum tube type, and an amplifier 11,

which mayalso be ofthe vacuum tube type, having an output circuit connected to line. 5 towhich it supplies detected or audio frequencycurrents in the well known manner.

Radiotransmitting station D comprises a modulator1'2of the vacuumtube type to the input a circuit of which a vacuum tube oscillat0r13 and a transmission circuit 8 are inductively coiinected,"the output circuit of the; modulator 12 serving to supply modulatedoscillations to the input circuit of vacuuln tube amplifier '48 which connects modulator 12 to transmitting antenna. 14.

Willbeclear from'the description of Fig. 1, signal variations originating at station A produce corresponding variations in line 8 to which station A is connected by the central station circuit. Signal currents from line 8 'andradiofrequency oscillations from oscillator 13 are supplied to modulator 12 by whichmodulated oscillations of radio frequency are transmitted to amplifier 48. Amplified modulated oscillations are impressed upon antenna 14and their energy is radiated in the ordinary manner. Ampli fierAS and modulator 12 are asymmetrically conducting and consequently no signals will betransmitted in overlines 8 when oscillations are set up in antenna 14 by radiant energy from another source. Radiant electrical energy from a distant station it of proper frequency, will set up electrical os- .5, serves therefore as a channel forlincomin signals. It should be noted, however, that" V since'the incoming and outgoing channels are. con'ugately related at sta 1on B, there no ten ency for energytransnntted from statiouD vto be received at station C and cause singing of the'radio circuits even when antennae 9 and 14 are both tuned to the'frequency of the oscillations generated by oscillator 13. From one point of view, twoway signaling is carried on over. a single w re 7 channel from station A to'stat on B; oyer two two-wire one-way channels from station E to stations Gland D; and b two radio channels? to the distant signa 'ngl station which, as in the case of transatlantic communication, may be connected to. a system similar to that illustrated in Fig. 1. It will of coursecbe understood that there may be as manyfstations C for receiving and as many stations D for transmlttlng radlo messages as desired'nnd that any stat on C may be used with any station D regardless of their locations. g a v 'Refe ing to Fig. 2', which shows thecord circuits at the central station, a single signal station A, shown by Way example an ordinary are hone 'subs cri ers station, is

connected by inc-1, which'may'contain any number of toll lines and repeating stations, to the jack J, at the cent ral statlon B. The circuits at station B consist Of thIQG SQCtIOHS 15,116 and 17 which we be' respectively. a

termedthe line section, vt e re eating section and the artificial line or-ba nclngsection and are so designed as to automatically balance whether, the subscribers line and associated apparatus and the dperators set are connected or disconnected. Section '15 terminates in the tip and ring contacts of plug, P and is inductively related to repeat} mg action .16 by repeating coils 19. Normally, whenplug P isdisconnected from a jack; sectionil balances section 17. A conductor 20 containing an artificial impedance simulating the impedance of subscribers sta tion A and its transmission circuit 1 is normally bridged across section 15 and a corresponding impedance conductor 21 is bridged across section 17 which is connected to repeating section 16 by coils 22. The character and value'ofthe inipedance's nsedinflconductors 20 and 21 [depend u 'n the characteristics of the line 1 whic is to-beibahv anced. Incoming currents from the radio receiving station traverse line 5, jackJ ing to the radio transmitting station is connected; The operators listening circuit 28 is inductively related to sections 15 and 17 by similartransforrners 29 and so does notdisturb theebal ance of the two sections and their connected circuits. The operators talking" circuit 30 may be connected across section 15 by means of key 31 and the same operation of V the? key closes circuit 32. bridged across section 17 and containing an artificial operators talking circuit desig-.

nated generally by numeral 33,.this. artificial circuitserving to balance and its connected apparatus Upon removing the receiver I from: its switchhook, the subscriber at station'A closes the usual circuit from battery through one Winding of line relay ,34, back contact 35 of cut-0d relay 36, over line 1 and backvthrough circuit 30 front contact 37 of cut-off relay 36, a. sec- 0nd winding of line relay 34'and battery 38. Line relay.34 is energized, closing a circuit at contact'39 and causing the energization of si nal" device 40. The operator observ ing the energized condition of signal device 40rinserts plu P into the corresponding jack J compl from ground through winding of relay 36 to sleeve contacts of jack J and plug P, winding of relay 6, and battery to ground. Inits operation, cut-oflf relay 36 pulls up both its armatures slgnal element 40 to be deenermzed. Relay 6 is also energized and pulls up both its front and back armatures. .Another cirto ground. Relay44 in energizing, pulls up armature 49'openingthe circuit through.

answering supervisory lamp which was momentarily closed by the back armature of relay 6., Relay 44 moves the armature 46 from its back contactto the front cont-act,

thereby opening the bridge circuit 20 and closing {the talking current path through non-inductive resistance 47 in shunt to the winding of relay 42. The impedance characteristic of circuit 20 should be as nearly as possible that of circuit 1 and its coneting an energizing circuit 1' for cut-ofl relay 36 which may be tracedv 35 and 37, permitting- 'netitfednpparatus. The operator in efi'ect ciitdcir'cuit'fitl otl'the line. and substitutes the refor an equivalent impedance without disturbing the impedance balance of section 15 against section 17. If nowthe opera'tor closes her talking key 31 so as to bridge circuit- 30 across line section 15, C11- is simultaneously closed, throwing tn tgziivalent impedance across section 17. tdf restoring key 31 cuts oil both cir- {ttlltsBO and 32 and the removal of plug ffblllfjadktl restores all circuits to thelr 'tirig ifin lcondition; It will be ap arentthat sections 15 and 17 are thus kept alanced at all times. Incoming signal currents are reiieatd lroincii'cuit 23 throu h coil 24 to section 16, and outgoing signal currents are im ressed from line 1 through repeating "col s 19 upon section 16 and circuit 27 which is bridgedtliereacross. Circuits 23 and '27 i [which connect the high frequency appaff'ratinlto the central statiomare in effect radio or toll lines by which one subscriber -ma'yjtommunicate with another. Q'Al'jthough circuits 23 and 27 have been qfsci'ibed in conncction with radio signalreceiving and transmitting systems reecti vely, it is obvious that any signaling rcui't comprising two one-way circuits constituting e ectrically independent incoming circuits such as disclosed herein to an ord L narytwo wire signaling line. In the case pparatus disclosed may be replaced by any btlier suitable radio transmitting and receiving tlfip altttllsn The system disclosed in aqua ywen be ap lied to other forms tric signaling an to electric selecting The invention is therefore not limited to the arrangement disclosed, y by the scope of the appended is claimed is: a In combination, means for receiving signal waves and for detecting'said a ntral station, an asymmetric rennel connected to said detecting 11s and terminating at said central stadependent means for transmitting rad: signal waves modified in accordance all el connected to said independent means tei niniiting at said central station, a way signal line terminating at said cenaft 1 stationland means at said central sta a, t ri for connecting said signal line to said transmitting channel and said receiving channel at will. f ,2. In combination, means for receiving tipp an asymmetricv receiving channel con-, .nected to said means and terminating at 4 1C said-station, independent means for transmitting carrier waves modified in accordsignal line at Will; 7

3. A signaling system comprising a trans- 'mitting' station, a receiving station, a subscribers station, and a central station con- 4 and outgoing channels may be connected by "(if-radio transmissiom-the particular radiov signals, an asymmetric transmitting detectingqcarrier waves, a central st'a-' ance with signals," an asymmetric transmittion, atWo-Way signal line terminating at said central station, .and a cord circuit for conjugately connecting said channels to said f station disconnected when said circuit is connected for simulating the impedance of said circuit and its associated apparatus.

6. In a signaling system, two asymmetric signaling channels, a two-wire circuit, a central station for connecting said channels to said circuit, said station comprising a repeating section in which said two signaling channels areconjugately connected, a

line section connected to said repeating section, and abalancing section simulating the impedance of said line section and. connected to said repeating sectioninsuch manner as to'balance said line section.

7. In a signaling system, two asymmetric signaling channels, a two-Wire circuit and, a central station for connecting said channels to said circuit, said station comprising a repeat-in section in which said two signaling channe s are conjugately connected, a line section connected to said repeating section, and a balancing section simulating the impedance of said line section and connected to said repeating section in such manner as to balance said linesect-ion, said station also comprising means disconnected when said circuit is connect-ed'for simulatingthe imllll pedance of said circuit and its associated apv paratus. v

p 8. Ina signaling system, two asymmetric signaling channels, a two-Wire circuit, a central station for connecting said channels to said circuit, means at said central station disconnected when said circuit is connected' forsimulatingthe impedance of said circuit and its associated apparatus, an operators set for the central stat-ion operator, 1

means for connecting said set to said circuit, and an artificial operators set controlled by said connecting means to automatically station.

1 9, In a system, two asymmetric signalinglchannels, a two wire circuit, and acentr'al station fonconnecting said signaling channels ,tosaid. circuit, said central 7 station comprising means for simulating the impedance of said two-wire circuit to bal- I ance the circuits at said central station with I any of saidincoming channels.

respect to said signaling channels, an operato'rs set-for the central station operator, means .for,,connecting said set to. said twowire circuit,-and an artificial operators set controlled lay-said connecting means to Vant i eilr ima atsaid centralstation. V

10. In combination, a plurality of asym- 'metr ic I incoming channels, a plurality of out-going channels, a plurality of subscribers lines, a central station and means whereby an operator at said central 'lostation may. connect anyof said subscribers lines to; any ofvsaid outgoing channels and 11. A' wireless telephone system ing a transmitting antenna, a receiving antenna, an operators station, a subscribers line terminating at said station, independent asymmetric channels connected to said antennae and terminating atsaid station,

and means at said station comprisingcord circuits for conjugately connecting said channels to saidline at will, a

12. A signaling system comprising a, plu' rality' of radio transmittingstations, a plurality'of radio receiving stations and .a pluf 'rality of signaling stations, andimeans for connecting said signaling stations to any one of said transmitting stations and any one nfgsaidreceiving stations. o h --13. In combination, a central station, a snbscrihers station, a two-way signaling circuit connecting said subscribers station to central station, a plurality of one-way carrier channels terminatingat 'said central station, and a cord circuit at said central .station, having a two-Wire termination and a four-wire termination for connecting said two-way circuitto two of said carrier channels.

14., A telephonesystemcomprising a high frequency incoming channel, a high frequency outgoing channel normally physically disconnected therefrom, a plurality of 7 subscribers ,lines, and operators cord "cirone of said lines-at will.

cuits for; connecting said cchannels to. any

7 I15. Atelephone system comprising a high frequency incoming channel, a high fre 'uency outgoing channel normally physically disconnected therefrom, a plurality of subscribers" lines and an operatorscord circuit having alcon jugate. four-wire termination and a two-wire termination for connectlng said channels to any of'said lines at will.

,, 16. A wireless telephone system compris 'ing a transmitting antenna, a receiving antain the circuit balance compristenna, a subscribers station and an operators station for connecting said subscribers station to both of said antennae, said operators stationcomprlsing means to simulate the impedance of said subscribers station when said subscribers station is disconnected.

17. 'A wireless telephone system comprising a transmitting antenna, a receiving antenna,a transmission line and an operators station for connectlng sald transmlssion line to both of said antennae, said operators station comprising a network simulating the characteristic impedance of said transmisslon line.

,18. In combination, two separated stations, ,two central operators stations associated respectively with said separated sta tions by signal lines, an asymmetric channel for transmitting electrical waves in one direction between said central stations, a separate asymmetric channel for transmitting electric waves in the opposite directionbe-' tween said central stations, and an operators cord circuit at each central station for conjugately connecting. the twov asymmetric channels at said central station to the associated signal line at will.

19. In a signaling system, two separated stations, two asymmetric channels. connecting said stations, each of said channels comprising means for producing high frequency carrier currents, means for modulating said currents in accordance with signaling cur- .rents, a' circuit for transmitting low fre-' quency signal currents from one of said statrons tO'ItS associated modulator, means for detecting the modulated high frequency currents, a circuit for transmitting. the low.

frequency detected currents to the other of said. stations, a two-way signaling line and an operators cord circuit having means for conjugately connecting the terminals of the two asymmetric channels at one of said stations to said two-way'signahng line.

In a signaling system, twoseparated stations, two, asymmetric channels connect ing said stations, each of said channels comprising'means for producing high frequency,

carrier currents, meansfor modulating said carrier currents in accordance with signal currents, a transmitting antenna for radiating the energy of said carriercurrents and a receiving antenna for receiving sa1d rad1-' ated energy, a circuit for transmitting low frequency signal currents from one of said stations to its associated modulator, means for detecting high frequency currents, a circuit for transmitting the low frequency de tected currents to the other of said stations, a two-way signaling line, and an operators cord circuit having means for conjugately connecting'the terminals of thetwo asymmetric channels at one of said stations to said two-way signaling line.

21. In combination, a plurality of widely separated radiotransmission stations, aplura ity of widely separated radial receiving stations, a plurality of subscribers stations 6 and means whereby a central station operator may connect any of said subscribers stations simultaneously to any of said radio transmitting stations and any of said radio receiving stations.

22. In combination, a central station, v physically separate high frequency incoming and outgoing channels terminating thereat, .a subscribers station, a line connected to said subscribers station and terminating at said central station, an operators circuit at said central station whereby an operator mayconverse either over said channels or over said line, and an operators cord cirhole to said line at will.

23. In a signaling system, a radio transmitter and radio receiver having connections leading to a common point, a plurality of wire communication channels con-. nected to said point, link circuits for interconnecting any wire communicating channel with the radio transmitter, and receiver, and means associated with said link circuits for enabling the operator to talk and listen either on the radio circuit or on the wire circuit.

24:. In a signaling system, a radio transmitter and radio receiver having connections leading to a common point, a plurality of wire communication channels connected to said point, link circuits for interconnecttuit for conjugately connecting said c-han ing any wirev communication channel with the radio transmitter and receiver, and means associated with said link circuits for permitting the operator to monitor the connection without interrupting it.

25. In a signaling system a radio transmitter and radio receiver having connections leading to a common. point, a plurality of.

wire communication channels connected to said point, link circuits for interconnecting any Wire communicating channel with the radiotransmitter and receiver, and switch ing means associated with said link circuits to enable the operators set including the transmitter and receiver to be connected with the Wire circuit or the radio circuits independently. v i

26. In a signaling system a radio transmitter and radio receiver having connections leading to a common point a plurality of wire communication channels connected to said point, link circuits for interconnecting any wire communicating channel with the radio transmitter and receiver, and switching means associated with said link circuits for enabling the operators set including transmitter and receiver to be connected independently either to'the wire or radio part of the system and to permit the receiver to be associated with the connection between the radio and wire part-of the system without interrupting it.

In witness whereof, I hereunto subscribe my name this 19th day of May, A. D. 1923.

HERBERT E. SHREEVE. 

